<!doctype html>
<html lang="en">

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Bootstrap demo</title>
  <!-- 引入CSS -->
  <link href="bootstrap/css/bootstrap.min.css" rel="stylesheet">
</head>

<body>
  <div class="container-fluid mt-3">
<div class="dropdown">
  <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton1" data-bs-toggle="dropdown"
    aria-expanded="false">
    Dropdown button
  </button>
  <ul class="dropdown-menu" aria-labelledby="dropdownMenuButton1">
    <li><a class="dropdown-item" href="#">Action</a></li>
    <li><a class="dropdown-item" href="#">Another action</a></li>
    <li><a class="dropdown-item" href="#">Something else here</a></li>
  </ul>
</div>
  </div>

  <!-- 引入JS -->
  <script src="bootstrap-5.2.3-dist/js/bootstrap.min.js"></script>
</body>

</html>